Now I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ’s afflictions for the sake of his body, that is, the church, of which I became a minister according to the stewardship from God that was given to me for you, to make the word of God fully known, the mystery hidden for ages and generations but now revealed to his saints. To them God chose to make known how great among the Gentiles are the riches of the glory of this mystery, which is Christ in you, the hope of glory. Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ. For this I toil, struggling with all his energy that he powerfully works within me.  – Colossians 1:24-29 (ESV)

It is not easy or fun to let God start working on us and shaping and molding us to be more like Him.  There are times when things need to be added, but there are also times when God removes things, like a surgeon, to get the old and the bad out.  But like most things that require hard work, it will be worth it all in the end.